RockNES

This is a nice emulator with many features, including a "eagle" mode which
should make games look better.
On my old PC I noticed RockNES wasn't particulary fast. But with both the
advance of PC's and RockNES the speed difference (compared to other emulators)
should be neglible.

After the first run, RockNES creates a ROCKNES.CFG file which can be edited
with any text editor to set options for sound, video, controllers etc.

RockNES also supports the Game Genie, see the ROCKNES.TXT file included
in the ZIP file for more information on how to use Game Genie codes with
RockNES.